Electrical wiring system and ejectable device therein

ABSTRACT

Electrical devices such as outlet receptacles and switches provided with built-in safety-fuse elements which are adapted to be inserted into housings forming part of a wiring system network, particularly in multi-story buildings, embodying feed wires extending vertically through the several stories of the buildings, without need for conventional panel boards. Each of the devices incorporates its own circuit breaker upon the occurrence of an electrical fault in the wiring or in the unit connected thereto, at which time the device is ejected, at least partially, from its housing to indicate the location of the fault, and the point of interruption of the electrical service in the system which is protected thereby.

United States Patent [191 Gittin et al.

[ June 26, 1973 1 ELECTRICAL WIRING SYSTEM AND EJECTABLE DEVICE THEREIN [75] Inventors: Alvin S. Gittin, 1900 South Eads St.,

Arlington, Va. 22202; Ralph E. McDonald, 1 1717 Larry Road,

Fairfax, Va. 20230 [73] Assignee: Said McDonald to said Gittin [22] Filed: June 25, 1971 211 Appl. No.; 156,616

Related U.S. Application Data [63] Continuation-impart of Ser. No. 867,024, Oct. 16,

1969, Pat. No. 3,612,953.

[52] U.S. Cl 337/206, 337/216, 337/265,

337/271, 339/34, 339/147 P [51] Int. Cl. I-IOlh 85/30 [58] Field of Search 337/4, 5, 79, 142,

[56] References Cited UNITED STATES PATENTS 3,139,498 6/1964 Linton 337/244 UX 2,256,716 9/1941 Klahcnik..... 337/216 X 930,675 8/1909 Menzel 337/271 1,959,211 5/1934 McNamara 337/269 1,488,263 3/1924 Mandra 337/267 3,612,953 10/1971 Gittin et a1 337/206 UX FOREIGN PATENTS OR APPLICATIONS 653,899 12/1934 Germany 337/150 Primary Examiner-Bemard A. Gilheany Assistant Examiner-F. E. Bell Attorney-Samuel Lebowitz [57] ABSTRACT Electrical devices such as outlet receptacles and switches provided with built-in safety-fuse elements which are adapted to be inserted into housings forming part of a wiring system network, particularly in multistory buildings, embodying feed wires extending vertically through the several stories of the buildings, without need for conventional panel boards. Each of the devices incorporates its own circuit breaker upon the occurrence of an electrical fault in the wiring or in the unit connected thereto, at which time the device is ejected, at least partially, from its housing to indicate the location of the fault, and the point of interruption of the electrical service in the system which is protected thereby.

18 Claims, 21 Drawing Figures PAIENTEDJWB 191a WEFEWQ INVENTORS S. GET TIN ,LPH E. CD

ATTORNEY PAIENIEDmzs I873 3 742 1 sum 3 a; Q

INVENTORS ALVIN S. GITTIN RALPH E. MCDONALD ELECTRICAL WIRING SYSTEM AND EJECTABLE DEVICE TI-IEREIN This application is a continuation-in-part of our application Ser. No. 867,024, filed Oct. 16, 1969, now US. Pat. No. 3,612,953, Oct. 12, 1971.

This invention relates to an electrical wiring system for multistory buildings and more particularly a system adaptable to the wiring of modern high-rise buildings, which eliminates the need for panel boards at the different levels of the building.

It is the object of the present invention to provide an electrical wiring system for multi-story buildings which is economical in initial construction, as well as maintenance, and which is characterized by many safety features which are more than adequate to comply with the minimum code requirements for providing adequate power for anticipated loads.

It is another object of the invention to provide an electrical wiring system for multiple story buildings which embodies a plurality of feed wires extending in vertical directions from the service entrance box, with electrical devices accommodated in housings which are inserted in the vertical feed wires in substantialvertical alignment, with such devices incorporating selfcontained safety fuses for the protection of the wiring system and the electrical units attached thereto, without need for individual panel boards with circuit breakers or safety fuses therein at the different levels of the building for distribution of the electric power therefrom.

The provision of individual fusible safety links in the electrical devices wired into the vertical feeders, with provision for the automatic ejection of the devices from their housings upon the rupture of the fusible links, makes possible the easy detection of any fault in the system when such is caused either by a short-circuit of any appliance which may be connected in the system, or by a high resistance fault which presents a fire hazard and which eventually leads to a conflagration. This reduces maintenance costs in the course of troubleshooting.

The wiring system in accordance with the invention, with the electrical devices such as outlet receptacles and switches arranged in substantially vertical alignment, results in tremendous economies over present systems of wiring. Thus, not only are the cost of the panel boards and the connections thereto eliminated, but the amount of material and labor which is entailed in the stringing and connecting the feed lines from the panel boxes in horizontal and vertical directions around doorways and through the vertical studs, is reduced substantially, resulting in great economies.

Furthermore, the increased safety accruing from the provision of fusible links at each electrical device, such as outlet receptacles and switches, reduces fire hazards as well as more serious injuries arising from the insertion of foreign metal objects within the openings of the outlet receptacles. The individual and immediate blowing of a safety fuse in one outlet receptacle excludes black-outs which normally are caused by the "blowing" of a fuse in a panel board, as usually occurs when a fault arises in any branch circuit or feeder line, which incapacitates these lines and all electrical units connected thereto.

The proximity and the distribution of thefusible individual links forming part of each individual electrical device connected to the vertical feeders and the immediate rupture thereof, would greatly reduce the incidence of fire resulting from a high-resistance fault in the wiring system which engenders heat and ultimate burning, without necessarily actuating the fuse or circuit breaker in the panel box, as has been the case heretofore. Furthermore, the fault is more easily located in proximity to the ejected switch or outlet.

The provision of safety outlets throughout the wiring system eliminates the possibility of overloading any part of the wiring system.

It is another object of the invention to provide rugged and economical electrical devices, such as outlet receptacles and switches, which may be fitted with safety fuses of different capacities in dependence upon the circuit needs, and the failure of which may be indicated readily so that another operative device may be substituted therefor to re-establish the necessary circuit conditions upon the removal of the faulty electrical unit therefrom, the location of which may be determined with relative definiteness by virtue of the proximity of the ejected device to the faulty electrical unit or wiring.

The electrical devices in accordance with the invention, embodying housings for ejectable outlet receptacles and switches, also may be installed in existing wiring systems to realize all of the advantages accruing from these devices even though they may not form components of vertical wiring arrangements.

While outlet receptacles for attachment plugs, as well as switches, have been provided heretofore with fuse devices therefor, as described in US. Pat. Nos. 2,086,861, July 13, 1937, and 2,256,716, Sept. 23, 1941, none has incorporated the advantageous features as disclosed herein, and especially the feature of the automatic ejection of the device from its housing upon the blowing of the fusible link.

Other objects and purposes will appear from the detailed description of the invention following hereinafter, taken in conjunction with the accompanying drawings, wherein FIG. 1 is a perspective view of a duplex outlet receptacle for attachment plugs, each incorporating a safety fuse, and the lower one shown in ejected position arising from rupture of the fusible link in the interior thereof;

FIG. 2 is a perspective view of the outlet receptacle adapted to be inserted interchangeably in the casing provided therefor, which is wired into the vertical feeders extending through a plurality of stories of the buildmg;

FIG. 3 is a perspective view of a toggle switch adapted to be inserted into a housing therefor and which is wired into the vertical feeders extending vertically through the several stories of the building for the control of overhead ceiling lights or other electrical units;

FIG. 4 is a front elevation of the casing of a duplex outlet receptacle adapted to be mounted within an outlet box mounted within the building wall and which is covered by the ornamental plate shown in FIG. 1, with the sockets therein for receiving the ejectable outlet receptacle bodies;

FIG. 5 is a horizontal sectional view along line 55 of FIG. 4, with the outlet receptacle shown in FIG. 2 indicated in operative position in the upper socket of the casing;

FIG. 6 is a horizontal sectional view of the outlet receptacle body shown in FIG. 2, showing the arrangement of the contact terminals therein;

FIG. 7 is a view similar to FIG. 6 showing the arrangement of the parts upon the blowing of the fuse within the outlet receptacle body arising from a shortcircuit or other fault in the electrical unit which is adapted to be connected to the outlet body by means of an attachment plug;

FIG. 8 is a vertical sectional view along line 88 of FIG. 6 with the fuse mounting shown in solid lines when the outlet body is operative, and with the fuse mounting in dotted lines upon the rupture of the fuse as indicated in FIG. 7;

FIG. 9 is a perspective view of a structural detail for supporting the fusible link shown in FIGS. 6, 7 and 8;

FIG. 10 is a schematic view of a multi-story building showing the feed wires extending upwardly through the several stories, with electrical devices wires therein in substantially vertical alignment at laterally displaced points of the building, for example, casings for mounting outlet receptacles for attachment plugs in some of the feed wires, while others are wired with housings for receiving ejectable control switches in accordance with the invention;

FIG. I1 is a front elevation of a duplex outlet receptacle incorporating another embodiment of a' safety fuse ejecting mechanism;

FIG. 12 is a perspective view of one of the ejectable units;

FIG. 13 is a vertical longitudinal sectional view of the body shown in FIG. 12, with certain parts in elevation;

FIG. 14 is a horizontal sectional view generally along line 14-14 of FIG. 13;

FIG. 15 is a sectional view similar to FIG. 14, showing the positioning of the parts in response to the rupture of the safety fuse;

FIGS. 16 to 119 are different views of another embodiment of a safety fuse in a modified assembly thereof with the ejecting mechanism shown in FIGS. 13 to 15;

FIG. 20 is a horizontal sectional view similar to FIG. 14 of still another embodiment of the invention; and

FIG. 21 is a view similar to FIG. 115 showing the positioning of the parts in response to the rupture of the safety fuse in FIG. 20.

In FIG. 10 of the drawings a multiple story building B is shown schematically, having vertical feed wires I and 2 extending upwardly through the several floors F and into which are wired electrical devices 3 and 4, respectively. These feed wires are run from a service inlet from a main panel board at a lower level of the building and are distributed around the building to provide housings 3 for outlet receptacles 0 in substantially vertical alignment at the several levels of the building for connection of floor lamps, table lamps, or other electrical units thereto. Another feeder 2 is designed to have connected thereto at the different levels of the building, housings 4 for control switches S which are connected to overhead ceiling lights L, and which control the operation of the latter. It is understood that these vertical feeders l and 2 are illustrative of many which are spaced laterally around the perimeter of the building and which extend vertically, to satisfy the need for switches and outlets for the electrical units and appliances to satisfy the demands for electric power in the building, in dependence upon the functional needs of the building, whether it be for apartments, offices or the like.

The arrangement of the distribution of the wiring feeders is indicated schematically in FIG. I0, which makes possible connection of the electrical units thereto without need for any panel boards at the differ ent levels of the building which normally are provided with adequate circuit breakers in conformity with the requirements of the electrical building codes. The latter are replaced by devices in accordance with the invention which are connected to the vertical feeders and which are fitted with the necessary safety devices which function is normally performed by circuit breakers within the panel boxes. The devices in accordance with the invention meet these needs to a degree superior to that afforded by the conventional panel boxes, so that the latter may be eliminated and realization may be had of the advantages accruing from a system of wiring which need be run mainly in vertical directions with a minimum of wiring extending in horizontal directions, with the consequent reduction in costs of labor and materials entailed in cutting through vertical studs and across doorways and other building components.

The electrical devices in accordance with the invention are illustrated in the remaining figures of the draw ings, and FIG. I shows one of the duplex outlets which may be used interchangeably with single outlets, which are adapted to be wired into the vertical feeders ll extending through the building walls at laterally displaced points therealong.

As shown in FIGS. 4 and 5, the duplex outlet 3 may be formed of a casing of insulating material defined by a front wall ill, lateral walls 12, 12 and a rear wall 14. The casing is preferably formed of molded plastic material, such as Bakelite, and may be reenforced by a metallic band 33 extending across the vertical median of the rear face thereof, and which extends transversely therefrom adjacent to the top and bottom edges of the casing and wherefrom it is bent in vertical directions to form mounting flanges 28 at the front of the casing. The mounting flanges 28 are provided with slightly elongated slots 29 therein for receiving fastening screws 30 which engage threaded lugs formed in the outlet box mounted within the building wall, which expedients are conventional and well known in the art. In the case of the duplex outlet shown in FIG. 4, a threaded opening 34 is provided at the mid-portion of the front wall for receiving a threaded bolt 32 for mounting an ornamental plate P in overlying relation to the casing 3, as shown in FIG. I.

The ornamental plate P above and below the fastening screw 32, is provided with openings of the same contours as the sockets 20 in the casing and in overlying relation thereto for the insertion into the sockets of outlet bodies I), the fronts of which are shown in FIG. I and a rear perspective view of which is shown in FIG. 2. These bodies 0 are formed of any desired hard plastic material such as Bakelite and may be constituted by upper and lower members M and 42 joined together along a horizontal median plane 43. The outlet body is provided with openings 40,40 in the lateral walls thereof from which protrude parts of spring-detent members M and M, described in greater detail below, which serve to latch the body 0 within its socket 20 in the operative state of the fusible link therein, and which retract upon its rupture to permit the body to be ejected automatically from its socket.

The components 41 and 42 of molded plastic may be formed with the required passages and chambers for accommodating the circuit-making elements of the outlet body when the same is inserted into one of the sockets in the casing shown in FIG. 4.

The top surface 44 of the body is provided with a central lug or keyway 47 of predetermined width which is limited by lateral recesses 48,48 extending to the rear wall 49 of the body. The bottom surface 45 of the body 0 is plane conforming to the plane base walls 19 of the sockets 20, while the lateral walls 46,46 have a curvature conforming to the lateral walls 21 of the sockets 20. The latter are provided with projections 17 at the junctions of the upper walls of the sockets with the lateral walls 21, leaving a gap or groove 18 between the projections, which compels the insertion of the body 0 with the upper wall of the body always on top, which arises from the accommodation of the keyway 47 within the groove 18. This structural arrangement renders impossible the insertion of the body 0 in an upside-down position. The width of the keyway provides a reliable indication for the thermal rating of the fuse link in the body 0. Thus, if the housing 3 is wired to accommodate a load of 5 amps, groove 18'therein is of a predetermined width which will receive a body 0 with a lug 47 of corresponding width, or smaller, but which will block an outlet body of greater capacity, such as amps, in which case the keyway 47 is wider.

The front 50 of the body 0 is provided with vertical slots 51 and 52 of unequal length and a rounded slot 53. Conductive terminals are provided on the interior of the body 0 in communication with each of the slots so that those in communication with the slot 51 are connected to the neutral terminal of the distribution system, those connected to the slot 52 are connected to the hot side of the line, while the terminal communicating with the opening 53 leads to a grounding terminal.

The safety fuse is connected to the hot side of the line so that when any fault arises in the electrical unit which is plugged into the outlet body 0 by way of the prongs of an attachment plug leading from the electrical unit (not shown), through the vertical slots 51 and 52, the fuse blows and the outlet body 0 is automatically ejected from its socket for a limited extent, as indicated for the lower body 0 shown in FIG. 1, to indicate which unit is faulty and requires disconnection. This does not affect the continuity of the power supply to the upper outlet which is mounted in the casing 3.

The automatic ejection of the outlet body in response to a fault in the electrical unit connected thereto, may be realized in many different ways, and the arrangement shown in FIGS. 5 to 9 is illustrative of many possible arrangements for attaining this result.

The outlet casing 3 which is affixed within the outlet box in the building wall (not shown), may be provided with its own ground, while supporting means for automatically ejecting the outlet body 0 upon the blowing of the thermal fuse therein. Thus, the grounding strap 13 extending vertically across the rear of the casing may be stamped with a circular opening 15 along a plurality of radial lines and the inner ends of the several radii 16 may be turned along curved lines to engage the outer end of a spiral spring 17', as clearly shown in FIG. 8.

Each outlet body is adapted to be inserted into its socket and latched therein following the compression of the spring as shown in FIGS. 5 and 8, so that the spring exerts a resilient force to eject the body, which force is resisted by the spring detent members mentioned above, as long as the fusible link in the outlet body 0 is maintained in operative position. When the fuse blows, these spring detent members are released so that the ejecting spring 17 is free to exert its influence to eject the outlet body from its socket at least to a limited degree, as shown in the case of the lower body in FIG. 1, thereby to indicate the blowing of the fuse therein.

The casing shown in FIGS. 4 and 5 is designed to have the neutral conductor of the feed wire 1 connected thereto at screw 27 and the hot wire at screw 27 These screws are mounted in conductive members 25 and 25', respectively, which terminate in contact terminals 26, 26' of generally C-shaped allochiral relationship. The electric current is designed to pass from these terminals to the conductive terminals within the outlet body 0 disposed in the chambers in the latter and from there through the projecting prongs of an attachment plug connected to an electric unit, which prongs are'inserted into the electrical body through slots 51 and-52.

As stated above, the outlet body is provided with spring detent members on each side thereof which perform the dual function of completing the electrical circuit between the wire terminals of the casing to the prongs of the attachment plug and at the same time function as balanced latching members which effectively resist the force of the expulsion spring 17 as long as the thermal fuse is effective, but which is incapacitated both as an electric conductor and latch by the blowing of the fuse.

. Thus, as may be seen in FIGS. 6 and 7, the metallic contact member M from the hot side of the line is retained within the body of the outlet receptacle along the length 60 thereof, wherefrom it is bent inwardly at the reentrant portion 61 in an inclined direction, and thereafter it is bent outwardly along a short straight length 63 to tip 64 wherefrom it is bent inwardly along a curved terminal portion 62. A metallic conducting piece 84 extends from length 60 of contact member M, to which is soldered the base element of the fuse 80 at point 83. The vertical leg 82 of fuse 80 is threaded from point 83 through aligned openings 87 in the top and bottom flanges 86,86 of a spacer I of insulating material (FIG. 9), beyond which the fusible element has a narrowed portion 81 which determines its rating. The end of the fuse is affixed to the terminal connector 57 seated within chamber.54 and with which cooperates a jaw of metallic material in juxtaposed relation thereto for accommodating one of the prongs of the attachment plug which is inserted into the slot 52. The connector 57 is affixed to the body of the outlet receptacle by having the vertical extension 56 thereof bolted to the spacer block 55 between the chambers 53 and 54 The companion metallic detent member M, of generally similar contour at its outer end as is member M, is contained within the body 0. The confined end of member M is retained within chamber 53 formed in the body 0 wherefrom the reentrant portion 71 is bent inwardly and passes therefrom to the short straight portion 73 to the curved tip 74, wherefrom the member is curved at its terminal portion 72 with a curvature generally of C-shaped contour adapted to be accommodated within the terminal 26 on the interior of the easing 3, and which is allochirally related to the terminal portion 62 of leaf spring member M.

When the outlet body is in operative condition, the retainer member I is disposed vertically, as shown in FIGS. 6 and 8, and the opposite edges 85 of the intermediate wall 85 between flanges 86, are effective as fulcrum points for the metallic leaf springs M,M' adjacent to the bases of the reentrant portions which are adapted to be flexed from the positions shown in solid lines in FIG. 6, to those shown in dotted lines as the body is inserted into the socket 20. The inner faces of the lateral walls of the casing 22, 22' may be tapered in the direction of insertion of the body, as indicated on an enlarged scale in FIG. to facilitate the flexing of the free curved ends 62,72 of the metallic springs IVLM towards the interior of the body as the latter is moved inwardly. However, when the body 0 reaches its end position, the free ends of the springs M,IVI', which have been cammed towards the interior of the body, arrive opposite the contact terminals 26,26 and are now free to spring outwardly into the solid line positions shown in FIG. 6, at which time they assume a nested position within the terminals 26' and 26, respectively, of the casing (FIG, 5). In this position the body is seated securely to receive the projecting prongs of an attachment plug, but is biased in a condition to be ejected if the fuse in the body should blow. When this happens, the inclined straight lengths 61 and '71 of the metallic springs IVLM serve to cam the upper portion of the insulating retainer I into the dotted line position shown in FIG. 8, so that the normal resilience of the metallic springs M,M' drives the portions of the conductors adjacent the curved tips 64 and 7 3 thereof free of the outer walls of the body into the interior of the latter through openings 40,40, as indicated in FIG. '7, so that spring 17' is free to exert its force against the end of the body to eject it from the casing to the limited extent indicated in FIG. l. The ejection of the body 0 at the lower end of the plate P does not affect the circuit of the electrical unit which may be connected to the upper body 0, so that there is no complete black-out in the room, as generally occurs when a fuse blows in a panel box. The partial ejection of the outlet receptacle body renders easy its removal from the socket for inserting a replacement. Even in the absence of a replacement, the concealed contacts 26, 26' at the rear of the socket minimizes any danger of injuries by accidental contact therewith. The extent of the ejecting movement of the body may be controlled by the force of the spring and the difference in length thereof between its compressed condition, as shown in FIGS. 5 and 8, and its freely extended position (not shown).

FIG. 6 also shows a grounding conductor 91 within the ground opening $3 of outlet receptacle body 0, which may be connected to the rear face of the body and which terminates in a circular portion against which the inner end of spring 17' presses to eject the body when the fuse blows. The grounded terminal 91 thus communicates with the metallic strap 13 and the attachment flanges 28 to constitute an effective ground for the outlet when a grounded terminal is necessary.

FIGS. Ill to 19 illustrate variant embodiments of ejectable outlet receptacles which are automatically ejected from the casing upon the occurrence of a short circuit in an appliance which may be connected to the outlet receptacles or which may blow upon the insertion of any shorting device into the slot connected to the hot terminal line.

FIG. 11 1 shows a front view of a duplex outlet receptacle in which the parts similar to those described in the previous embodiment have the same corresponding reference characters, and the features of which may as well be applied to a single outlet receptacle unit.

The outlet receptacle body 0' shown in FIGS. 11 to 15 may be formed of molded insulated upper and lower units and 101, respectively, and may be integrated by a threaded bolt 102 extending therethrough, as is well known in the art. The spaced slots 51 and 52, for receiving the connecting prongs of the attachment plug A are fitted with lateral spaced terminal members which are connected with the electric terminals of the power line within the outlet casing 3. In order to insure the insertion of the outlet receptacle 0' within the easing 3 in one mode or direction only, a lug 103 extends inwardly in the socket of the casing, which cooperates with a longitudinal slot 104 in the external wall of the body 0, so that the latter cannot be inserted in an upside-down position.

A ground terminal R05 is disposed within the body opposite the grounding slot 53, and constitutes one end of a metal strap 105 which is mounted on a pedestal within the body by screw-threaded bolt 106, and which is extended beyond the inner end of the body and terminates in a resilient leaf spring 107, which serves as the ejecting spring of the body upon rupture of the fusible link within the body. This leaf spring 107, pressing against the rear metal wall of the casing 113, serves as a ground for the outlet receptacle which is completed by connecting the ground wire of the system between bolt M2 and a mounting flange therefore 112' projecting laterally from the upper portion 113 of the metallic casing 113, as shown in FIG. 13.

The lateral walls of the casing provide longitudinal camming surfaces for the sloping or inclined contact terminals 122 and 132 which protrude from openings in the lateral walls of the body, and which automatically complete the circuit with the opposite electric terminals of the power line when the outlet receptacle body 0 is inserted completely within the casing 3.

As clearly shown in FIGS. 13 to 15, the terminal behind the slot 52 is of bifurcated form, for embracing one of the male prongs of the attachment plug A, and the rear portion thereof is connected to the fusible link 1154) by means of soldering the opposite ends of the latter at 151 and 152 to the U-shaped base of terminal 120 and the wing of a pivoted yoke within the body. The yoke means is formed of two members 140 and Mil of similar outline, which are pivotally connected at by means of a pintle extending through their inner ends, and which are provided with terminals of reduced cross-section M2 and 143 at their outer ends, as clearly shown in FIG. 16 and 19. The outer end 142 engages an opening 123 in electrically conductive member 121, the inner end 1211 of which is locked within the body I00 of insulating material while the outer end is formed as a resilient finger and is shaped to provide a contact terminal 122 which serves both as a latching member for the body as well as a terminal connector for the hot side of the power line. The latter is connected to metallic bar 108 by fastening bolt 110. The conductive member 121 is of springy material which is normally biased towards the interior of the body, as indicated in FIG. I15, and the circuit from the terminal 120 is completed by way of the fusible link 150 and the wing 140 of electrically conductive material which penetrates the opening 123 in the resilient finger 121 and completes the circuit to the hot side of the power line by an inwardly turned flange 122 making contact with flange 108' turned inwardly from metal strap 108. On the other side, the terminal 130 behind the slot 51 is formed of a continuous length of spring metal 131 having an S-shape at one end and terminating in a free end 132 having an inclined camming surface and capable of serving as a latch at the inwardly turned flange 132, as is the case with terminal 122. The wing 141 of the yoke member is formed of insulating material, and the free end 143 thereof engages the opening 133 in conductive member 131 in the set" or operative position of the fuse device, which makes contact with the neutral side of the power line at bolt 111.

Both conductive members 121 and 131 are normally biased to spring inwardly towards the interior of the body, as indicated in FIG. 15, by virtue of their resiliency adjacent to the free ends thereof. The device is cocked for operation by setting the ends of the yoke member within the recesses 123 and 133 and by soldering the fusible link at its opposite terminals 151 and 152, as indicated in FIGS. 13 and 14. With the device conditioned for operation, as shown in these figures, the body is inserted into the socket of the casing, which results in a limited bending of the free ends of the terminal members 122 and 132 to the positions indicated in dotted lines in FIG. 14, and upon their arriving to the inner end of the socket within the casing, the free ends 122,132 snap outwardly through openings 124 and 134, respectively, to engage the metallic straps 108 and 109 of the socket at the inward projections 108 and 109' thereof, respectively.

In order to relieve the mechanical strain on the fusible link 150 in the course of insertion of the outlet receptacle within the body, a safety device may be provided which in the embodiment shown in FIGS. 13 and 14 is in the form of a flexible tie 153 which is looped along the pivotal shaft 145 of the yoke member and which extends through the slots 51 and 52 at the front of the body and is tied thereat by means of a button 154 or other fastener. This button may bear indicia relevant to the fusible link, for example, its rated capacity, and may serve as a certification seal of the unit to indicate that the same was never used before. Following the insertion of the body within the receptacle, the flexible loop is severed, in order to provide freedom of action for the yoke member in conjunction with the fusible link 150 in the event of the occurrence of a short- 4 circuit occasioned by inserting a foreign metallic object within the slot 52, or a fault in the device connected to the attachment plug A. The resulting rupture of the link 150 makes possible a freedom of action of the conductive members 121 and 131, as indicated in FIG. 15 which removes the latching effects of the terminal contacts 122 and 132 against the lateral terminals 108' and 109', which in turn permits the spring action between leaf spring 107 and the rear strap 113 of the casing to eject the body to a limited extent, as indicated in FIGS. 1 and 15. 4

FIGS. 16 to 19 illustrate a variant form of safety device formed of substantially rigid material rather than of a flexible cord or other material, as shown in FIGS. 13 and 14. In this construction, a bar 164 of insulating plastic material, having an upstanding arm 165 at its inner end, in engagement with the insulated wing 141 of the yoke, extends through the base of slot 51 of the outlet receptacle and is provided with a downwardly directed arm 166 at its outer end, which extends below the slot in engagement with the front face of the outlet receptacle. A nick or groove 167, at the junction of the front end of the bar 164 and the downwardly extending lug 166 renders the latter readily frangible from the bar, so that upon the completion of the insertion of the outlet receptacle into the casing, the safety device may be removed. In view of the fact that the bar is disposed at the bottom of the slot 51, which is deeper than the slot 52, its presence at the bottom of the slot as shown in FIG. 18, affords no impediment-to the insertion of the prong of the attachment plug into slot 52.

FIGS. 16 to 18 also illustrate a modified form of mounting the fusible link between the yoke and the terminal 120. The fusible link is formed of a wire of a fusible alloy having a predetermined rating which ter- 'minates in enlargements 161 and 162. Slots 163 may be provided in in the upper edge of conductive wing member 140 as well as in the base of terminal 120 so that the fuse may be conveniently set therein with or without additional soldering.

Another form of combined contact and latching assembly for the outlet receptacle within the socket of the casing, is illustrated in FIGS. 20 and 21. In this embodiment, the terminal behind slot 52 is of generally S-shaped configuration which is seated within a chamber within the body 100. One end of the fusible link 180 is soldered to the inner end of the conductive member 170 and the opposite end is soldered to an intermediate portion of a pivoted arm 171 which is pivotally mounted at 172. The arm 171 is biased for movement in a counter-clockwise direction by relatively strong leaf spring 185, but is restrained from such movement as long as the fusible link 180 maintains op-' erative connection between terminal 170 and the arm 171. The latter is provided at its outer end remote from the pivot 172 with, a recess 173 through which is adapted to move a plunger 175, which may be of rectangular section as shown in the drawing. The recess is of corresponding contour but of slightly larger dimensions. The inner end of the plunger is provided with an enlarged head 177 against which a spiral spring 178 of relatively little force acts to force the plunger outwardly. The opposite end of the plunger is-provided with a camming edge 176 which serves to permit the inward travel of the body into the socket of the casing without binding. When the body is inserted into the latter to the limit, the plunger is cammed inwardly beyond the flange 108 of the power line terminal, whereupon the force of spring 178 acts on the enlarged head 177, to latch the free end of plunger into contact with the terminal 108 which is connected to the hot side of the power line.

The circuit is completed by the connection of the terminal 188' behind slot 51, likewise of S-shaped outline with the other side of the power line. The inner end 188a of the terminal is connected with the curved end 109a of the electric terminal 109 connected to the other side of the power line. The parts remain in operative and latched condition as long as no fault occurs. However, when a short circuit arises, the rupture of the fusible link 180 makes possible the operation of the leaf spring which has sufficient force to overcome that of the coiled spring 178 and which causes the plunger 175 to travel inwardly as indicated in FIG. 21 to remove both the latching effect and electrically conductive effect of the plunger, whereupon the leaf spring 1107', which may be affixed to the rear of the casing, exerts its ejecting force against the inner end of the body to eject the same partially, as illustrated in FIG. 21.

As described above, the walls of the socket may be provided with an inclination to facilitate the camming action on the end of the plunger, in the course of inserting the body into the socket of the casing.

As stated above, while FIGS. ll, 4 and 11 illustrate a duplex outlet receptacle, the casing 3 may be formed with a single socket 20 adapted to house a single outlet receptacle body. Such a casing may be used to house and eject a control toggle switch S, as shown in FIG. 3, which is provided with spring detent members M, M, of a construction similar to that described in connection with the outlet'receptacle 0. The casings for the switches may be of the duplex type to accommodate a pair of such switches if such are desirable. Of course, the switch housings 4 for the ejectable switches S, while of similar constructions as the housings for the outlet receptacles 0, are positioned at higher levels above the floor as shown in FIG. 10.

It is understood that the casings 3 and 4 for outlet receptacles or switches may be substituted for conventional units in outlet boxes in existing wiring systems, to attain the advantages of the instant invention.

We claim:

1. An electricaloutlet device comprising a. a casing provided with a socket at the front thereof and spaced power-line connecting means on opposite sides of said socket in the interior thereof,

b. a body having a pair of spaced slots at the front thereof for receiving corresponding prongs of an attachment plug, and a pair of spaced terminals in said body in alignment with said slots,

c. electrically conductive members extending from said spaced terminals and comprising substantially congruous resilient fingers having the free ends thereof adapted to protrude from openings in the opposite sides of said body for engagement with said power-line connecting means,

d. a fusible link in circuit with one of said terminals,

e. resilient means between said casing and the rear end of said-body and biased to exert an ejecting force on the latter,

f. spring detent means connected to said fusible link for retaining said body within said casing and said electrically conductive members in circuit with said power-line connecting means, as long as said fusible link is in circuit-making position, and adapted to be disabled upon rupture of said fusible link to permit said resilient means to eject said body from said casing, at least partially,

g. said electrically conductive members each comprising a resilient portion adjacent to each finger, normally biased to spring said free ends into said body, pivoted yoke means in engagement with said resilient portions to maintain said resilient portions in extended position for engagement with said power-line connecting means, and means responsive to the rupture of said fusible link to inactivate said yoke means to permit said resilient fingers to spring into said body and said resilient means to exert its ejecting force.

2. A device as set forth in claim 1, including safety means connected to said yoke means for relieving the transmission of any mechanical strain to said fusible link in the course of insertion of said body into said casmg.

3. A device as set forth in claim 1, wherein said yoke means comprises a pair of wings pivotally connected together at their inner ends with the outer end of each wing in engagement with an opening provided in the resilient portion of each conductive member, one of said wings being of conductive material with said fusible link connected therefrom to one of said spaced terminals, and the other one of said wings formed of insulating material for only mechanical connection with the other one of said spaced terminals.

4. A device as set forth in claim 3, wherein said wing of conductive material is connected with the hot line of the power-connecting means.

5. A device as set forth in claim 3, including safety means connected to said yoke means for relieving the transmission of any mechanical strain to said fusible link in the course of insertion of said body into said casing, comprising a substantially rigid bar extending between the wing of insulating material and the front of said body adjacent to said last-mentioned terminal, said bar having a readily frangible portion at the front of said body to inactivate'said safety means following the insertion of said body into said casing.

6. A device as set forth in claim 3, wherein said fusible link connected to the wing of conductive material is constituted by a low-melting point wire of predetermined rating, with enlargements at the opposite end thereof adapted to be readily engaged with a slotted opening in at least said last-mentioned wing.

7. A device as set forth in claim 1, wherein said safety means comprises a flexible tie member extending around the pivotal mounting of said wing members and through the spaced slots at the front of said body adapted to be severed following the insertion of said body into said casing.

8. An electrical outlet device comprising a. a casing provided with a socket at the front thereof and spaced power-line connecting means in the interior thereof,

b. a body having a pair of spaced slots at the front thereof for receiving corresponding prongs of an attachment plug, and a pair of spaced terminals in said body in alignment with said slots,

c. electrically conductive members in circuit with said spaced terminals having the ends thereof remote from said terminals adapted to engage said power-line connecting means with at least one of said ends functioning with the latter as both mechanical latching means as well as electrically conductive means,

d. a fusible link in circuit with one of said spaced terminals and electrically conductive members,

e. resilient means between said casing and the rear end of said body and biased to exert an ejecting force on the latter, and spring detent means, for retaining said body in mechanically latched position within said casing, and in circuit-making position between said spaced terminals and said power line connecting means, as long as said fusible link is in circuit-making position, and adapted to be disabled upon-rupture of said fusible link to permit said resilient means to eject said body, at least partially, from said casing.

9. A device as set forth in claim 8, wherein said fusible link is in circuit with the spaced terminal and electrically conductive member connected to the hot-side of the power line.

10. A device as set forth in claim 8, wherein both electrically conductive members are adapted to have the free ends thereof in engagement with the powerline connecting means in mechanically latching and electrically conducting engagement.

11. A device as set forth in claim 10, wherein said power-line connecting means are on the opposite sides of said sockets, and with the free ends of the electrically conductive members in engagement therewith being disposed in allochiral relation.

12. A device as set forth in claim 11, wherein said power-line connecting means in said socket terminate in concavely shaped seats, and correspondingly contoured surfaces on the free ends of said conductive members for nesting engagement within said seats.

13. A device as set forth in claim 8, including an additional terminal within said body spaced from said pair of terminals opposite an additional opening in the front of said body adapted to accommodate a grounding prong of an attachment plug, and electrical connections between said additional terminal and easing adapted to have a ground connection in circuit with the latter.

14. A device as set forth in claim 13, wherein said last-mentioned circuit includes said resilient means in said casing which effects the ejection of said body.

15. A device as set forth in claim 8, wherein said spaced power-line connecting means are disposed in proximity to the rear of said socket.

16. A device as set forth in claim 15, wherein the walls of said socket in front of said power-line connecting means are flared toward the front thereof for guiding the free ends of said electrically conductive members into circuit-making position'upon the insertion of said body within said socket.

17. An electrical outlet device comprising a. a casing provided with a socket at the front thereof and spaced power-line connecting means on opposite sides of said socket in the interior thereof,

b. a body having a pair of spaced slots at the front thereof for receiving corresponding prongs of an attachment plug, and a pair of spaced terminals in said body in alignment with said slots,

c. electrically conductive members extending from said spaced terminals and comprising substantially congruous resilient fingers having the free ends thereof adapted to protrude from openings in the opposite sides of said body for engagement with said power-line connecting means,

d. a fusible link in circuit with one of said terminals,

e. resilient means between said casing and the rear end of said body and biased to exert an ejecting force on the latter,

f. spring detent means, comprising said resilient fingers, connected to said fusible link for retaining said body within said casing and said spaced terminals in circuit with said power line connecting means, and

g. a spacer of insulating material within said body between said resilient fingers for supporting said fusible link and maintaining said resilient fingers in extended position through said openings in the operative condition of said fusible link, said spacer adapted to shift its position upon rupture of said fusible link to effect the withdrawal of said resilient fingers into said body to permit said resilient means to eject said body from said casing, at least partially.

18. An electrical outlet device comprising a. a casing provided with a socket at the front thereof and spaced power-line connecting means on opposite sides of said socket in the interior thereof,

b. a body having a pair of spaced slots at the front thereof for receiving corresponding prongs of an attachment plug, and a pair of spaced terminals in said body in alignment with said slots,

c. electrically conductive members extending from said spaced terminals for engagement with said power-line connecting means,

d. a fusible link in circuit with one of said terminals,

e. resilient means between said casing and the rear end of said body and biased to exert an ejecting force on the latter,

f. spring detent means connected to said fusible link for retaining said body within said casing and said electrically conductive members in circuit with said power-line connecting means, as long as said fusible link is in circuit-making position, and adapted to be disabled upon rupture of said fusible link to permit said resilient means to eject said body at least partially from said casing,

g. said electrically conductive members comprising an electrically conductive transversely reciprocating bar in circuit with said fusible link provided with a camming edge at the outer end thereof for enabling inward movement of said bar in the course of insertion of said body into said casing, spring means for forcing said bar into electrical contact and in latching mechanical engagement with the electric terminal connected to the hot side of said power line, and a lever system with secondary spring means of greater force than that of said first-mentioned spring means connected to said bar for compelling the movement thereof in the reverse direction in response to the rupture of said fusible link. 

1. An electrical outlet device comprising a. a casing provided with a socket at the front thereof and spaced power-line connecting means on opposite sides of said socket in the interior thereof, b. a body having a pair of spaced slots at the front thereof for receiving corresponding prongs of an attachment plug, and a pair of spaced terminals in said body in alignment with said slots, c. electrically conductive members extending from said spaced terminals and comprising substantially congruous resilient fingers having the free ends thereof adapted to protrude from openings in the opposite sides of said body for engagement with said power-line connecting means, d. a fusible link in circuit with one of said terminals, e. resilient means between said casing and the rear end of said body and biased to exert an ejecting force on the latter, f. spring detent means connected to said fusible link for retaining said body within said casing and said electrically conductive members in circuit with said power-line connecting means, as long as said fusible link is in circuit-making position, and adapted to be disabled upon rupture of said fusible link to permit said resilient means to eject said body from said casing, at least partially, g. said electrically conductive members each comprising a resilient portion adjacent to each finger, normally biased to spring said free ends into said body, pivoted yoke means in engagement with said resilient portions to maintain said resilient portions in extended position for engagement with said power-line connecting means, and means responsive to the rupture of said fusible link to inactivate said yoke means to permit said resilient fingers to spring into said body and said resilient means to exert its ejecting force.
 2. A device as set forth in claim 1, iNcluding safety means connected to said yoke means for relieving the transmission of any mechanical strain to said fusible link in the course of insertion of said body into said casing.
 3. A device as set forth in claim 1, wherein said yoke means comprises a pair of wings pivotally connected together at their inner ends with the outer end of each wing in engagement with an opening provided in the resilient portion of each conductive member, one of said wings being of conductive material with said fusible link connected therefrom to one of said spaced terminals, and the other one of said wings formed of insulating material for only mechanical connection with the other one of said spaced terminals.
 4. A device as set forth in claim 3, wherein said wing of conductive material is connected with the hot line of the power-connecting means.
 5. A device as set forth in claim 3, including safety means connected to said yoke means for relieving the transmission of any mechanical strain to said fusible link in the course of insertion of said body into said casing, comprising a substantially rigid bar extending between the wing of insulating material and the front of said body adjacent to said last-mentioned terminal, said bar having a readily frangible portion at the front of said body to inactivate said safety means following the insertion of said body into said casing.
 6. A device as set forth in claim 3, wherein said fusible link connected to the wing of conductive material is constituted by a low-melting point wire of predetermined rating, with enlargements at the opposite end thereof adapted to be readily engaged with a slotted opening in at least said last-mentioned wing.
 7. A device as set forth in claim 1, wherein said safety means comprises a flexible tie member extending around the pivotal mounting of said wing members and through the spaced slots at the front of said body adapted to be severed following the insertion of said body into said casing.
 8. An electrical outlet device comprising a. a casing provided with a socket at the front thereof and spaced power-line connecting means in the interior thereof, b. a body having a pair of spaced slots at the front thereof for receiving corresponding prongs of an attachment plug, and a pair of spaced terminals in said body in alignment with said slots, c. electrically conductive members in circuit with said spaced terminals having the ends thereof remote from said terminals adapted to engage said power-line connecting means with at least one of said ends functioning with the latter as both mechanical latching means as well as electrically conductive means, d. a fusible link in circuit with one of said spaced terminals and electrically conductive members, e. resilient means between said casing and the rear end of said body and biased to exert an ejecting force on the latter, and f. spring detent means, for retaining said body in mechanically latched position within said casing, and in circuit-making position between said spaced terminals and said power line connecting means, as long as said fusible link is in circuit-making position, and adapted to be disabled upon rupture of said fusible link to permit said resilient means to eject said body, at least partially, from said casing.
 9. A device as set forth in claim 8, wherein said fusible link is in circuit with the spaced terminal and electrically conductive member connected to the hot-side of the power line.
 10. A device as set forth in claim 8, wherein both electrically conductive members are adapted to have the free ends thereof in engagement with the power-line connecting means in mechanically latching and electrically conducting engagement.
 11. A device as set forth in claim 10, wherein said power-line connecting means are on the opposite sides of said sockets, and with the free ends of the electrically conductive members in engagement therewith being disposed in allochiral relation.
 12. A device as set forth in claim 11, wherein said power-line connecting means in said socket terminate in concavely shaped seats, and correspondingly contoured surfaces on the free ends of said conductive members for nesting engagement within said seats.
 13. A device as set forth in claim 8, including an additional terminal within said body spaced from said pair of terminals opposite an additional opening in the front of said body adapted to accommodate a grounding prong of an attachment plug, and electrical connections between said additional terminal and casing adapted to have a ground connection in circuit with the latter.
 14. A device as set forth in claim 13, wherein said last-mentioned circuit includes said resilient means in said casing which effects the ejection of said body.
 15. A device as set forth in claim 8, wherein said spaced power-line connecting means are disposed in proximity to the rear of said socket.
 16. A device as set forth in claim 15, wherein the walls of said socket in front of said power-line connecting means are flared toward the front thereof for guiding the free ends of said electrically conductive members into circuit-making position upon the insertion of said body within said socket.
 17. An electrical outlet device comprising a. a casing provided with a socket at the front thereof and spaced power-line connecting means on opposite sides of said socket in the interior thereof, b. a body having a pair of spaced slots at the front thereof for receiving corresponding prongs of an attachment plug, and a pair of spaced terminals in said body in alignment with said slots, c. electrically conductive members extending from said spaced terminals and comprising substantially congruous resilient fingers having the free ends thereof adapted to protrude from openings in the opposite sides of said body for engagement with said power-line connecting means, d. a fusible link in circuit with one of said terminals, e. resilient means between said casing and the rear end of said body and biased to exert an ejecting force on the latter, f. spring detent means, comprising said resilient fingers, connected to said fusible link for retaining said body within said casing and said spaced terminals in circuit with said power line connecting means, and g. a spacer of insulating material within said body between said resilient fingers for supporting said fusible link and maintaining said resilient fingers in extended position through said openings in the operative condition of said fusible link, said spacer adapted to shift its position upon rupture of said fusible link to effect the withdrawal of said resilient fingers into said body to permit said resilient means to eject said body from said casing, at least partially.
 18. An electrical outlet device comprising a. a casing provided with a socket at the front thereof and spaced power-line connecting means on opposite sides of said socket in the interior thereof, b. a body having a pair of spaced slots at the front thereof for receiving corresponding prongs of an attachment plug, and a pair of spaced terminals in said body in alignment with said slots, c. electrically conductive members extending from said spaced terminals for engagement with said power-line connecting means, d. a fusible link in circuit with one of said terminals, e. resilient means between said casing and the rear end of said body and biased to exert an ejecting force on the latter, f. spring detent means connected to said fusible link for retaining said body within said casing and said electrically conductive members in circuit with said power-line connecting means, as long as said fusible link is in circuit-making position, and adapted to be disabled upon rupture of said fusible link to permit said resilient means to eject said body at least partially from said casing, g. said electrically conductive members comprising an electrically conductive transversely reciprocating bar in circuit with said fusible link provided with a camming edge at the outer end thereof for enabling inward movement of said bar in the course of insertion of said body into said casing, spring means for forcing said bar into electrical contact and in latching mechanical engagement with the electric terminal connected to the ''''hot'''' side of said power line, and a lever system with secondary spring means of greater force than that of said first-mentioned spring means connected to said bar for compelling the movement thereof in the reverse direction in response to the rupture of said fusible link. 